Have a 1999 S10 Chevy Pickup. Drove a couple of miles to the gas station. Went to back out and noticed the truck was in 4 wheel drive. I didn't even put it in 4 wheel drive. Tried to hit the 2 wheel drive button on the dash and the small light beside the button started to blink. My truck is stuck in 4 wheel drive, will not go back to 2 wheel drive.
So, my question is how do I get my 1999 S10 Chevy Pickup out of 4 wheel drive, and back to 2 wheel drive?
The first thing to do is to have someone with a scanner check the computers to see if there any trouble codes stored in the computer memory.
If none are found and the Transfer Case Shift Control Module is communicating properly then the next thing to check is to see if the Front Propeller Shaft Speed Sensor and the Rear Propeller Shaft Speed sensors are working properly
The system is automatic, when the computer senses that the Front Propeller Shaft is at a different speed than the Rear Propeller Shaft then the system will shift into Four Wheel Drive. When the two shafts are at the same speed then the computer will shift it back into Two Wheel Drive.
The flashing light on the dash is telling you there is a problem. It should stay lit when it is in four wheel drive. The light is controlled by the Transfer Case Shift Control Module
Checking the speed sensors out is the first thing to do. If this all checks out and the sensors are working properly and there are no trouble codes, then it will probably be a mechanical problem where your local transmission shop or dealer should take a look at it.
Let us know how you make out.
If you need more information, we are here to help anytime.
Hope you didn't go to all that trouble before checking both fuses on driver side dash behind the door and the ATC fuse under the hood. Then if you still have no success you may have a faulty vacuum line. But usually it is a fuse and if you have lights on the buttons it is most likely the ATC fuse under the hood. If you still have no luck then get the computer stuff. Fixed a Chevy S-10 with the automatic transfer case (ATC). Was stuck in 4 wheel Hi had all the lights working so it couldn't be the fuse in the cab so checked the one under the hood and the ATC fuse was blown needed a 20 amp fuse to fix.
Had the same problem with 2002 S10. Bought and replaced the actual switch for $39.00 and still had the same problem stuck in 4WD. Took off negative battery cable for 30 minutes after checking the fuses and they were good . Re hooked the negative cable cranked truck and was still in 4WD, pushed the 2 WD button and presto back in business. So try to disconnect the battery and let the computers reset. Wish I would have done that before I spent the $39.00.